package com.lianrui.web;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.Locale;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.support.RequestContextUtils;
import org.springframework.web.servlet.view.freemarker.FreeMarkerView;
import freemarker.template.SimpleHash;
import freemarker.template.Template;
import freemarker.template.TemplateException;

public class MyFreeMarkerView extends FreeMarkerView {

	@Override
	protected void doRender(Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception {
		super.doRender(model, request, response);
		Locale locale = RequestContextUtils.getLocale(request);
		
		exposeModelAsRequestAttributes(model, request);
        SimpleHash fmModel = buildTemplateModel(model, request, response);
        
        /*
         * 在这里我们默认生成静态文件,当ModelAndView有指定STATIC_HTML = false时,就不会输出HTML文件
         * 例如：ModelAndView modelAndView = new ModelAndView("htmlTest");
         * 	modelAndView.addObject("STATICHTML", false); 
         */
        if(Boolean.FALSE.equals(model.get("STATIC_HTML"))){
            processTemplate(getTemplate(locale), fmModel, response);
        }else{
            createHTML(getTemplate(locale), fmModel, request, response);
        }
	}

	public void createHTML(Template template, SimpleHash model, HttpServletRequest request, HttpServletResponse response) throws IOException, TemplateException, ServletException {
		//站点根目录的绝对路径
        String basePath = request.getSession().getServletContext().getRealPath("/");
        String requestHTML = this.getRequestHTML(request);
        
        //静态页面绝对路径
        File htmlFile = new File(basePath + requestHTML);
        if(!htmlFile.getParentFile().exists()){
            htmlFile.getParentFile().mkdirs();
        }
        
        /*
         * 如果静态页面已经存在,就不再创建静态页面.
         */
        if(!htmlFile.exists()){
            htmlFile.createNewFile();
            Writer out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(htmlFile), "UTF-8"));
            //处理模版  
            template.process(model, out);
            out.flush();
            out.close();
        }
        /*将请求转发到生成的htm文件*/
        request.getRequestDispatcher(requestHTML).forward(request, response);
	}
	
	/**
     * 计算要生成的静态文件相对路径.
     */
    private String getRequestHTML(HttpServletRequest request){
        
    	//web应用名称,部署在ROOT目录时为空
        String contextPath = request.getContextPath();
        
        //web应用/目录/文件
        String requestURI = request.getRequestURI();
        
        //basePath里面已经有了web应用名称，所以直接把它replace掉，以免重复
        requestURI = requestURI.replaceFirst(contextPath, "");
       
        //将.do改为.htm,稍后将请求转发到此htm文件
        requestURI = requestURI.substring(0, requestURI.indexOf(".")) + ".htm";
         
        return requestURI;
    }
}
